Oak Ridge Reservation: Public Health Assessment Work Group
Public Health Assessment Work Group
July 8, 2003 - Meeting Minutes
ORRHES Members attending:
Bob Craig (PHAWG Chair), George Gartseff, Tony Malinauskas, Peggy Adkins, Susan Kaplan, Pete Malmquist, David Johnson, and James Lewis
Public Members attending:
Tim Joseph, Danny Sanders, Ernest Hurd, Gordon Blaylock, R.L. Ayers, John Merkle, Janet Michel, and Bob Peelle
ATSDR Staff attending:
Bill Taylor, Jack Hanley, and Melissa Fish
Bob Craig called the PHAWG meeting to order and attendance was noted for the record.
There were five items on the agenda.
- Meeting minutes, June 16, 2003
- Update PHA project plan
- Update on the Health Statistics Review
- Update on the EPA Headquarters comments to ATSDR on the Uranium Y-12 PHA
- Introduction to Mercury (past exposures) for the Mercury PHA
The Draft meeting minutes for the June 16, 2003 PHAWG meeting were accepted as written without any modifications.
Update on Project Plan
Jack Hanley provided an update on the project plan. Jack Hanley told the group that at the last PHAWG meeting, the work group voted to make adjustments to the project plan. The original plan had both the mercury and the White Oak Creek Public Health Assessments coming out in August. However, the mercury Public Health Assessment will take longer. So, the work group agreed that White Oak Creek will be the first PHA with a tentative target date for releasing to the PHAWG by July 28th. August 4th will then be the day that the PHA is presented to the PHAWG. Jack Hanley also explained that the document that is presented on August 4th is an internal government draft that is shared with the EPA, DOE Headquarters, DOE Oak Ridge, the State, and the ORRHES. The document is also called the data validation version and is a working draft.
Bob Craig asked when the White Oak Creek working draft will be out for public comment. Jack Hanley said that he believes that by September 2nd, the PHAWG will have compiled and approved a list of comments. Jack Hanley described the process further by saying that August 13th is the deadline for getting concerns to Bill Taylor so that he can compile all of the comments, then the comments will be discussed the following Monday in a PHAWG meeting, and next the PHAWG will approve the comments by September 2nd.
Bob Craig asked if the entire ORRHES will comment on the data validation version or if ORRHES would just comment on the Public draft of the White Oak Creek PHA. Jack Hanley responded to Bob Craig by saying that on August 26th there is an ORRHES meeting scheduled. ORRHES will already have a copy of the data validation version. However, ORRHES usually depends on the PHAWG comments. Jack stated that if it is possible for PHAWG to finalize the comments before the next ORRHES meeting, the comments could then be voted on by ORRHES. Jack added that it would be helpful for ORRHES to vote on the comments during the August 26th meeting.
Bob Craig wonders how the change in the project plan will affect the timing of the mercury PHA. Jack Hanley responded that the project plan change moves the mercury PHA into September.
Jack Hanley told the group that Bill Taylor and he are the primary people working on mercury. Jack expects to be finished with his portion of the mercury PHA by the end of July. Past historical mercury releases are important and Bill Taylor will be presenting all of the past Dose Reconstruction information. Bill Taylor would like to step through the past mercury releases very carefully while obtaining PHAWG input. Jack Hanley pointed out that any delay with mercury will not result in a delay to the other public health assessments.
Bob Craig understands that the mercury PHA will result in a two-month slip without affecting the other PHAs. However, Bob is concerned about the Iodine-131 PHA. Jack Hanley responded by saying that Paul Charp is dealing with the iodine issue and that Paul and Jack will approach the National Cancer Institute to discuss the technical data that ATSDR is trying to interpret.
Update on the Health Statistics Review
Bob Craig reminded the group that ORRHES has made a request for state cancer data.
Pete Malmquist provided an update on the cancer data request. Pete told the group that Dee Williamson has received confirmation that the state will provide the information that ORRHES requested. The ad hoc committee plans to meet with Dee Williamson at her convenience in the next couple of weeks to review Dee’s outline and the work group’s expectations of the review. Dee Williamson will go to Nashville and meet with the state to get the information. The work group can expect to see Dee Williamson’s review sometime in October.
Update on the EPA Headquarters Comments to ATSDR on the Uranium Y-12 PHA
Bob Craig stated that at the last release of the Y-12 Uranium PHA, there was confusion regarding unofficial EPA Headquarters’ comments on a previous version of the Y-12 Uranium PHA. Since ATSDR has now received official comments from EPA Headquarters, Bob Craig wants to know if the official comments are significantly different from the previous unofficial comments.
Jack Hanley told the group that the official EPA Headquarters’ comments are very similar to the unofficial comments and that ATSDR feels that most of the comments have been addressed in the Public Comment version of the Y-12 Uranium PHA. Jack Hanley added that ATSDR will have a response for each comment and will address each comment in writing.
Jack Hanley added that in September, ATSDR will bring all of the public comments (including the EPA Headquarters’ comments) to the PHAWG where the group will step through each comment.
Bob Craig asked if the official EPA Headquarters’ comments are coordinated with the EPA Region 4 Office comments. Jack Hanley responded saying that the comments are not coordinated.
James Lewis stated that at the June 16th PHAWG meeting, it was indicated that the group would like an invitation to be extended to EPA Headquarters and EPA Region 4 to attend an ORRHES meeting for the purpose of addressing concerns related to the Oak Ridge site and for discussion of EPA procedures used when interacting with ATSDR and ORRHES. James would like to know if any efforts have been made to bring EPA to Oak Ridge.
Bob Craig said that he is not aware that the group is looking for additional EPA involvement. James Lewis referred Bob Craig to the June 16th PHAWG minutes so that he could read the motion that the PHAWG passed.
After reviewing the minutes Bob Craig asked if the EPA invitation had been extended through Elmer Akin. James Lewis replied that the group plans to take the recommendation of inviting the EPA to ORRHES so that ORRHES can endorse the decision.
Bob Craig wants to know who is responsible for drafting the letter. Bill Taylor responded that there had not been any agreement about the procedure for drafting a letter.
Bob Craig requests that someone volunteer to draft a letter. James Lewis volunteered to get together with Kowetha Davidson to discuss the draft letter.
For clarification, Jack Hanley reminded the group that the Agenda Work Group could send an invitation, but a formal letter must go through the ORRHES.
John Merkle asked Jack Hanley if he is still trying to contact Tom Widner about the calculations for uranium exposure duration. Jack Hanley responded saying that John Buddenbaum is going to check his calculations and respond. Jack added that ChemRisk has been very responsive.
Action Item Regarding Update on the EPA Headquarters Comments to ATSDR on the Uranium Y-12 PHA
- James Lewis will meet with Kowetha Davidson to discuss the EPA draft letter.
Introduction to Mercury (past exposures) for the Mercury PHA
Bill Taylor gave a presentation to the work group regarding the past exposures of mercury. Bill Taylor used 12 different overhead transparencies in his presentation. A copy of the 12 transparencies used during the presentation are located in the field office in the PHAWG meeting minute notebook.
Bill Taylor told the group that ATSDR is planning to organize the mercury PHA according to past and present exposures. Bill added that a lot of work under the present exposures category has already been completed and that ATSDR plans to provisionally adopt the Dose Reconstruction as the basis for evaluating past exposures.
For clarification, Jack Hanley stated that the Dose Reconstruction focuses primarily on mercury releases from lithium enrichment at Y-12.
Bill Taylor provided the work group with his academic background and stated that he is not an expert in mercury or the Dose Reconstruction Project work. Thus, the process that Bill Taylor will use will include getting input from the work group.
Bill Taylor provided an overview of what questions ATSDR will consider when discussing historical mercury releases (Past Exposures) from the Oak Ridge facilities with the PHAWG.
Bill Taylor explained that ATSDR made the decision to wait for the mercury Dose Reconstruction to be completed. So when it was completed ATSDR had to figure out how to incorporate the mercury Dose Reconstruction results into ATSDR’s work. ATSDR hired technical reviewers to look at the document and provide comments. The reviewers completed their technical reviews in 2001 and the document containing their comments will be released soon. Currently, the document is in the final review process with the agency. ATSDR will use the comments to consider the strengths and weaknesses of the mercury Dose Reconstruction.
Jack Hanley asked how many technical reviewers made comments about the mercury Dose Reconstruction. Bill Taylor responded that ATSDR hired five technical reviewers and that ATSDR had received extensive comments from those reviewers.
James Lewis stated that in the past, ATSDR has asked for additional sources of information. Jack Hanley responded by reminding the group that last April, ATSDR made a request for new information and to this day, ATSDR has not received any new material or comments that information is missing. Jack Hanley added that Task 2 was extremely comprehensive.
Both Jack Hanley and James Lewis reminded the PHAWG that ATSDR has reached out and provided an opportunity for the public to provide additional information and resources regarding mercury. Jack and James stated that if anyone feels that they have additional information that should be considered, now is the time to provide that information and/or resources to ATSDR.
Peggy Adkins wants to know if the information on overhead two takes into consideration the mercury burial sites, lost mercury, and the terrain. For example, Peggy said that the map in the front of the room (Extent of Mercury Contamination in East Fork Poplar Creek 100-Year Floodplain [prior to remediation in 1997]) makes sense only if you do not actually live in the area. People who actually live in the area know how exaggerated the ridges and the valleys are for the airflow. People also know that there are sink holes indicating underground water pathways. Peggy Adkins would like to see a topographical map that shows mercury burial grounds and underground locations where water could have been contaminated by mercury.
There was confusion among the group members about the burial grounds that Peggy Adkins referred to.
Peggy Adkins said that she is referring to any and all mercury burial grounds because if you are a resident your concern is not where the mercury actually came from, the concern is the mercury itself.
No one at the meeting spoke of any permanent mercury burial sites on the ORR.
Jack Hanley stated that the air pathway will be discussed in the mercury PHA. With regards to groundwater, ATSDR plans to look at the groundwater as a separate Public Health Assessment. The mercury Dose Reconstruction did not look at groundwater but ATSDR will evaluate all contaminants in groundwater in one separate Groundwater PHA.
Peggy Adkins feels that if there is a separate PHA for groundwater, then the mercury PHA will be flawed because it will not show the extent of damage to citizens outside the fence resulting from mercury contaminated water.
Tim Joseph said that DOE performs off-site groundwater sampling and he does not recall any mercury ever being found in any wells.
There was some confusion about the amount of mercury that was actually released. Jack said that the Dose Reconstruction identifies the primary ways that mercury was released and that the quantity of mercury released from the Y-12 plant has been analyzed at least twice. The Dose Reconstruction details how much mercury went through the air, surface water, and how much is left in the ground. Jack Hanley stated that Bill Taylor will be examining the issue and will explain how ChemRisk went back and reanalyzed all of the mercury material.
John Merkle stated that if the parts do not equal the whole, then the difference is unaccounted for. John Merkle added that if the Dose Reconstruction provides numbers as to how much mercury was lost and how much mercury is accounted for by estimate, then presumably any difference in the sum that was found and what is lost is unaccounted for.
Bill Taylor responded by saying that the discussion that John Merkle has brought up already exists in the Dose Reconstruction document and in the technical reviewer comments. Bill said that the issue will be raised again. However, until there is new data available ATSDR cannot do anything besides reflect and comment on the information that is in the Dose Reconstruction document.
R.L. Ayers expressed concern that no one has ever mentioned the mercury burial ground on Hampton Road in Scarboro. Jack Hanley replied that there were two municipal dumps and that there is no record of DOE using the municipal dumps for hazardous waste or materials. Jack Hanley added that this issue is discussed in the concerns section of the Y-12 Uranium Public Health Assessment.
Bill Taylor explained that the three different forms of mercury (shown on the overhead) have particular importance in specific pathways of exposure. For example, elemental mercury is primarily a hazard as an inhalation pathway. The Dose Reconstruction identified two pathways for inorganic salts, those pathways include ingestion and dermal contact. Organic mercury such as methylmercury is primarily a hazard through the ingestion of fish. Methylmercury accumulates in the flesh of fish.
Bob Craig thought that elemental mercury was also an ingestion concern. Jack Hanley explained that the primary route of exposure for elemental mercury is inhalation.
Bill Taylor explained that children who are exposed to methylmercury in utero are the most sensitive population; but methylmercury can have an affect on adults as well.
Gordon Blaylock asked where methylmercury accumulates in the body.
Jack Hanley explained to the group that when organic mercury is ingested, almost all of it is absorbed and easily gets into the blood and then goes to the brain. When inorganic salts are ingested, the body does not absorb as much. Most inorganic salts will pass through the body but some will get into the blood. But what is in the blood is different from organic mercury (methylmercury) and does not go to the brain and ends up being a kidney toxin.
Tony Malinauskas asked what property of mercury is in fillings. Bill Taylor explained that a combination of elemental mercury and other metals are used in fillings and that the American Dental Association feels that the combination is permanent and safe.
Bill Taylor told the group that regarding methylmercury, the absorption factor that is generally used and accepted in most studies is 95%.
Bill Taylor explained that the results from the Dose Reconstruction are doses. The way to evaluate doses is to compare the doses to comparison values. Before discussing comparison values, Bill Taylor showed the group some of the data for Wolf Valley Residents that came from the Dose Reconstruction report.
Bill Taylor explained that the X-axis on the two charts refers to years. For all of the populations considered in the Dose Reconstruction report the years are from 1950 to 1990, except that for the Wolf Valley residents the years are from 1953 to 1962.
John Merkel asked if the data on the line graphs represents the internal dose rate. Bill Taylor answered yes.
Bill Taylor said that the word dose is used in a lot of different ways. For example, if I take one aspirin tablet the dose may be 325 mg. 325 mg would be my dose. But it is also typical to consider body weight so that a person may also consider a dose in milligrams of substance per kilogram of body weight (mg/kg) and not just the milligram. Bill Taylor said that mg/kg/day, which is a dose rate, are the doses in the mercury Dose Reconstruction Project report.
Bill Taylor explained that assumptions are used when estimating doses. Some doses are estimated from environmental data such as soil or air sampling; some doses are estimated from modeling; and some are estimated from a combination of modeling air dispersion and a measurement of quantities released.
Bill Taylor explained that the Dose Reconstruction is looking at air pathways where elemental mercury would have traveled down the valley direction. Jack Hanley added that elemental mercury is a vapor that typically rises and goes into the atmosphere and sometimes the vapors travel for days and weeks.
Peggy Adkins asked if a site was tested toward Oliver Springs. Peggy’s aunt worked at K-25 and Peggy Adkins believes that mercury was released toward Oliver Springs.
Jack Hanley told the group that K-25 releases were primarily uranium and fluoride and that there will be a PHA for K-25 Uranium and Fluoride releases.
Bill Taylor explained that when using an RfD which is an EPA comparison value, everything below the line (RfD) is screened out and is considered not to be a health hazard. But where the data are above the comparison values, those doses are considered further in the evaluation.
John Merkle asked if the RfD is calculated from the NOAEL by dividing by a factor of conservatism or if it has an identity of it’s own. Bill Taylor responded saying that RfDs are calculated from NOAELs also using uncertainty factors.
Tony Malinauskas asked if mercury doses are cumulative and if the group should be looking at the area below the curve rather than the curve itself. Bill Taylor responded that it depends on the dose rate and whether elimination is faster than absorption or ingestion.
Gordon Blaylock commented that methylmercury accumulates in the central nervous system and has been found in older adults and may be linked to Alzheimer’s disease.
Bill Taylor stated that a dose high enough to cause irreversible damage is probably more important than the issue of whether mercury is cumulative or not.
Bill Taylor explained that comparison values are derived from no-observed-adverse-effect levels (NOAELs) and lowest-observed-adverse-effect levels (LOAELs) and that both are derived from studies, either human or animal studies. In the case of mercury, there are some good human data available but animal data are used as well. LOAELs and NOAELs are specific doses that come from specific studies and there are safety factors applied to those values in order to come up with comparison values.
Bill Taylor said that the reason for the difference in the comparison values presented in the last two columns of the table (ATSDR’s MRLs and EPA’s RfDs) is because the agencies have selected different studies and considered the merits of each study separately.
Bill Taylor acknowledged Bob Craig’s remarks and stated that ATSDR has a higher minimum risk level (MRL) for inorganic mercury compared to EPA’s reference dose (RfD) and that ATSDR has a lower MRL for elemental mercury compared to EPA’s RfD.
James Lewis wanted to know the logic behind different agencies choosing different values. He would like clarification as to why different studies were used. Bill Taylor’s response was that studies selected to establish an RfD or MRL may have been done at different times and a comparison value will reflect the study or studies that are selected.
Jack Hanley provided an example of different studies being used. Jack said that in the 1990’s EPA used a study of Iraqi people who had been eating grain contaminated with organic mercury. Jack said that this study was used to create an RfD because it was the only study that EPA had. But in the last few years, agencies have made changes based on newer studies. Two of these studies are the Seychelles study and the Faeroe Islands study in which people are consuming mercury-contaminated fish. The studies looked at mercury in the hair of mothers and looked for slight developmental effects in the children in island populations who consumed a lot of fish. ATSDR is interested in the fish pathway and not contaminated grain.
Bob Peelle said that the most recent mercury studies are from five to seven years ago. Jack Hanley replied that in the last year or two there have been updates to the Seychelles and Faeroe Island studies and that the two studies are continuously developing.
James Lewis feels that ATSDR needs to bring back more information about the type of information that went into the studies that helped to derive the comparison values and the NOAELs.
James Lewis and Bob Craig feel that ATSDR and the PHAWG should look at the elemental mercury ATSDR minimal risk level more closely because ATSDR’s MRL is lower than the EPA RfD. Bill Taylor agreed.
Bill Taylor explained that the Dose Reconstruction report discussed both EPA’s reference doses (RfDs) and reference concentrations (RfCs) and ATSDR’s minimum risk levels (MRLs). RfD, RfC, and MRL are all types of comparison values. ChemRisk discussed MRLs in the mercury Dose Reconstruction report but did not include MRLs in the graphs.
Bill stated that ATSDR and EPA use a similar procedure to derive comparison values However, ATSDR does not use comparison values to set clean-up levels and EPA may do so. Both agencies use a safety factor when extrapolating from animal data to humans and for other uncertainties in the database, but ATSDR does not extrapolate across different exposure routes and EPA does.
Jack Hanley added that the EPA will use an inhalation study to derive an internal RfD and ATSDR will not do that. ATSDR will only use inhalation studies to derive inhalation MRLs.
Jack Hanley and Bill Taylor clarified that the PHA will contain MRLs.
Peggy Adkins would like to know if it is appropriate to add the ingestion and inhalation doses together. Bill Taylor stated that if a population is exposed to two forms of mercury with a common target organ, then it may be appropriate to add doses. However, if the mercury is affecting different parts of the body, then it does not make sense to add the doses.
Bill Taylor told the group that ATSDR has lowered the MRL for methylmercury to 0.0003 mg/kg/day from the value (0.0005 mg/kg/day) that was used in the Dose Reconstruction report.
Bill Taylor explained that the table on this overhead is a summary list that depicts the populations and the exposure pathways that are discussed in the Dose Reconstruction Task 2 Report. Bill Taylor said that there are over 12,000 mercury doses presented in the Dose Reconstruction report and that there are 94 combinations of pathways and populations.
Gordon Blaylock asked about the source of methylmercury. Bill Taylor replied that the mercury that went into the creek can be converted into methylmercury through microorganisms in the soil.
Janet Michel stated a concern about mercury pathways. Janet Michel asked if a youngster would get any mercury from playing in the creek, catching tadpoles, wading in the creek, getting water all over themselves, and eating things from the water near Jefferson Circle and down closer to where East Fork pond was.
Jack Hanley stated that the scenario of children playing in the water is one type of scenario that was evaluated in the pathways of the Dose Reconstruction document. Jack pointed out that the Dose Reconstruction used a farm family to collect information. The family was asked questions about frequency and duration of activities related to playing in the water.
Janet Michel added that as a child she would go into the creek and that she grew up across the street from the farm family.
Bill Taylor told the group that the Dose Reconstruction calculates doses for both adults and children in different populations.
Having grown up along lakes and creeks, Peggy Adkins points out that people were not limited to one area, fishing people went everywhere. Peggy says that because of this, it is difficult to pinpoint one single location.
Jack Hanley said that studies usually figure a percentage. Although Jack is unsure about the procedure that the Dose Reconstruction document used, he said that studies often figure that a certain percentage of fish came from a particular area. Jack Hanley said that he will find out the procedure that the Dose Reconstruction document used to derive doses from fish.
Bill Taylor stated that this overhead provides an example of calculated doses that exceed the NOAEL.
John Merkel asked if this information refers to the typical or the worst case/ maximum exposure. Bill Taylor responded that the Dose Reconstruction looked at fish consumption in different ways. There were three different categories depending on how much fish was consumed. There are doses that were calculated for people who ate a lot of fish and those that ate less fish.
Jack Hanley stated that the three categories are not screening values; the categories are used to show a realistic exposure. Bob Peelle added that the categories were set up to try to show realistic exposures but that there were always arguments regarding how much fish people would really consume.
There was discussion about the size of fish that could be found in East Fork Poplar Creek. Gordon Blaylock pointed out that he has seen carp measuring 20 inches or longer all the way to New Hope.
Bill Taylor explained that this overhead is an overview of the results and conclusions in the Dose Reconstruction document for elemental mercury exposures and inorganic mercury exposures. Some exposures of both types of mercury exceeded the comparison values (RfDs) but none of the exposures to inorganic and elemental mercury exceeded the NOAELs.
Bob Peelle pointed out that the table showing the comparison of highest estimated doses to toxicity benchmark values (RfDs for all three forms of mercury for the major population groups in the Dose Reconstruction report) means less than one might think because they used animal studies.
Gordon Blaylock responded to Bob Peelle’s comment by saying that if the study is based on animals, a safety factor is used. Jack Hanley added that a safety factor is factored in when converting a NOAEL to a reference dose.
Bob Peelle said that most people do not care if a dose is safe for an animal; they care if the dose is safe for a person.
Bob Craig asked if ATSDR planned to take a closer look at the populations that exceeded the toxicity benchmark values. Bill Taylor said yes and added that the PHA will use ATSDR comparison values (MRLs) rather than EPA’s RfDs.
Bill Taylor explained that in this table, the numbers that exceeded the reference dose or NOAEL have been bolded. This table shows that the methylmercury doses to most fishing populations exceeded the comparison values.
Discussion Regarding Mercury
Jack Hanley and Bill Taylor assured the group that ATSDR’s PHA will include years on the X-axis of the graphs that it produces.
Bill Taylor stated that the group must be selective about material that ATSDR would like more of. Bill expects that ATSDR will be most concerned with doses that exceed the NOAELs as well as the doses that exceed ATSDR’s MRLs. Bill Taylor also told the group that consideration of the technical reviewer comments might change the estimated doses that ATSDR uses. The doses could either be raised above or lowered below the comparison values depending on the technical comments.
Peggy Adkins asked if there is a plan to take actual people from high dose areas who have been shown by a legitimate source to have high levels of mercury and actually study those people to find out what type of mercury poisoning they have or to look at the symptoms and test the people to see what type of mercury poisoning they have?
Bill Taylor told the group that currently there is not a plan to test individual people for mercury poisoning. Bill said that the exposure must first be evaluated in the PHA. After an exposure is evaluated and if warranted, ATSDR can make recommendations and then form an action plan.
Jack Hanley provided an example of the process that Bill Taylor mentioned. Jack Hanley said that modeling and risk assessments performed by various agencies indicated that PCBs could be a problem on Watts Bar and the Clinch River/Poplar Creek. Previous assessments showed an excess of one cancer in 1000. Based on that, ATSDR performed its own assessment and had similar conclusions. So, in 1997, to validate the models and risk assessments, ATSDR went out and drew the blood from 116 people who consumed large quantities of fish.
Jack Hanley stated that once a population is identified, ATSDR can perform additional tests. However, the population must be narrowed down. ATSDR cannot draw blood from every person. If a biological indicator is known, ATSDR might perform follow-up activities. Bill Taylor and Jack Hanley stated that a Public Health action plan would come after the Public Health Assessment.
James Lewis asked Peggy Adkins to define and explain the term “legitimate source.” Peggy Adkins defined a legitimate source as a 24-hour urine analysis followed by agitation with a compound that combines with positive mercury ions.
James Lewis asked if Peggy Adkins was referring to the test being performed by a physician or a reputable lab.
Peggy Adkins explained to the group that she has had mercury testing performed from at least three different labs and all the tests have shown extremely elevated levels of mercury. Peggy Adkins feels that she has the symptoms and is a textbook case. Peggy does not know what type of mercury poisoning she has and is someone that could be tested further. Peggy added that there are people who lived around her who have some of the same symptoms that she is experiencing. Peggy worries that mercury poisoning is being misdiagnosed as Multiple Sclerosis.
Peggy Adkins said that it seems that the group is always looking at old data and making nice charts but is never really helping anyone. There are some sick people who are still alive who were exposed to mercury. Many people were constantly eating fish that may have had high levels of mercury. Thus, the 95% confidence is frustrating because so many people have died and the group is not trying to do anything new. The group continues to rehash old studies and put new labels on them.
James Lewis appreciated the background and information that Peggy provided but still wants to know what the group considers to be a legitimate source or a legitimate technique. James feels that it is important to clarify what is considered legitimate and what is not considered legitimate.
Jack Hanley stated that ATSDR does not perform clinical diagnosis of individuals. If an individual is looking for diagnosis, ATSDR refers them to board certified occupational specialists.
James Lewis understands what Jack Hanley is saying. His point is that a procedure for identifying mercury poisoning should be laid out. James asked whether there are certain types of tests or procedures that are considered credible that are used for evaluating or monitoring mercury poisoning.
Jack Hanley told the group that perhaps ATSDR can look further into the methodologies used for monitoring mercury. ATSDR can present information regarding standard methodologies and standard protocols (if there are standard methods) that are used when testing and monitoring mercury.
Janet Michel told the group that Dr. John Rosen at Mount Sinai Hospital in New York is the world’s leading expert in chelating lead out of children. Janet also said that there is a woman at John Hopkins who is doing a lot of research. In addition there are a lot of doctors on the occupational and environmental list serve that could respond and provide information regarding the protocol for evaluating mercury poisoning.
Jack Hanley told the group that ORRHES has developed comment sheets. Jack encourages everyone to use the comment sheets to describe their issue and concerns so that ATSDR can specifically address individual concerns in presentations and/or in the PHA.
Commenting on a statement that James Lewis made earlier, R.L. Ayers explained that if one set of doctors makes a decision, that does not mean that the decision will coincide with the decision of another group of doctors because doctors have different ideas. R.L. Ayers said she worked with physicians for 47 years at the Veterans Medical Center and knows quite a few physicians and knows how their minds work. Mrs. Ayers knows that all physicians are not going to agree with each other, especially if there is an important issue that they should not always agree on.
John Merkel stated that the calculations in the Dose Reconstruction that go from releases to doses should be reversible in the sense that if a person is assumed to have retained a certain amount of an element, it is probably possible to estimate the external concentration and duration of exposure that was required to produce the effect.
Gordon Blaylock told the group that the biggest source of mercury now for the average person is canned tuna. Gordon believes that the regulation for mercury in fish is 1 part per million and he wondered if the fish in East Fork Poplar Creek exceed that regulation. Bill Taylor told him that he does not know.
Susan Kaplan asked what the doses of mercury are today compared to those people who lived along the creek in the past? Gordon Blaylock said that it would depend on the years that people lived along the creek.
Gordon Blaylock said that if people fished in East Fork Poplar Creek during the years with the highest releases, those people would probably get a higher dose. Bob Craig added that very little mercury is coming down East Fork Poplar Creek today compared to the 1950s.
Susan Kaplan said that current mercury exposures are additive to the exposures of the 1950s. Bill Taylor responded that it would depend on how much mercury was eliminated from the body between the 1950s and present day.
Bob Peelle pointed out that nobody measured the mercury content of fish in the 1960s when it was most important.
Gordon Blaylock said that people in the United States did not get excited about levels of mercury until high levels of mercury were discovered in Canada. Gordon said that fish with high levels of mercury were collected from Poplar Creek in approximately 1974 or 1975.
Janet Michel told the group that she has seen a Y-12 document from the 1950’s that discusses monitoring mercury in water four times a year.
Bob Peelle did not recall the document that Janet Michel is speaking of.
Gordon Blaylock stated that Y-12 was primarily concerned with atmospheric releases and inhalation. They did not consider releases to the East Fork Poplar Creek.
Peggy Adkins told the group that it would be wonderful to have marks on the (Extent of Mercury Contamination in East Fork Poplar Creek 100-Year Floodplain [prior to remediation in 1997] map that reflect the known burial sites for any type of mercury.
Jack Hanley told the group that most of the mercury was in buildings and it leaked out of pipes into the ground.
Peggy Adkins told the group that she would like to see the mercury seepage points marked on the map.
Bob Craig pointed out that most people did not purposely bury mercury.
Bob Peelle said that depending on the pH of the creek, the main source of mercury downstream was presumably the mercury cleaning device.
Action Items Regarding Mercury Discussion
- ATSDR will follow-up on Mrs. Ayers question about buried mercury wastes.
- ATSDR should identify the logic behind different agencies choosing different values, especially as it related to elemental mercury.
- ATSDR will look further into the methodologies used for detecting and monitoring mercury poisoning.
- ATSDR will find out the procedure that the Dose Reconstruction document used to derive estimated doses from fish.
Bill Taylor told the group that he will not be available for the July 21st PHAWG meeting and that the mercury discussion will resume in August.
R.L. Ayers will bring one of the very first Oak Ridge maps dated in the early 1950s to the next PHAWG meeting.
The meeting was adjourned at 7:30 p.m.